Heat olive oil in a large pot. Add diced onion and cook ‘till translucent. Add garlic and stir ‘till almost brown. Add water, broth and sweet potato. Bring to boil, and then lower to simmer. Add white potatoes, rice, and spices. Simmer until broth looks creamy – the sweet potato will break down and create a nice consistency- and the white potatoes and rice are tender. Stir in PB and spinach. Serve hot.